Fig. 37. — A Cactus Longicorn Beetle — Moncilema ciassum — which, in Texas, feeds on the joints of cacti, the 

 larva destroying the internal tissues of the attacked plant. (From "The Principal Cactus Insects of 

 the U.S.A.," Bulletin 113, Bur. Kntomol., IT.S.D.A., 1912, plate 1.) 



I'liolo.. r,„r.,iu nf T:„t.n,inln,lll. Lhpl. .1 ,/,-,V»//„rf . C.S.A. 



Fi... 3S. -Echi,wcncus. showing a black gum-like exudation, the resiUt of attack by the larva of 

 MoniiJimn crassum, which lives within aiul destroys the tissues. 



